1. Field of the Invention
The present invention relates to a fryer for the heating and cooking of foodstuffs with cooking oil filled into an oil vat.
2. Description of Related Art
In the food restaurant industry, for example in fast food restaurants, industrial fryers used in the preparation of deep-fried foods, such as the one shown in FIG. 5, are well known. In this fryer 1, the temperature of the oil filled into an oil vat 11 is maintained within a predetermined temperature range by heating control, and foodstuffs, such as potatoes for French fries, are put into the high temperature oil vat 11 and cooked.
As the oil degrades if it is continually used, it is necessary to C) periodically filter the oil with an oil cleaner 30. To filter the oil in the oil vat 11, a discharge valve lever 16 is operated to open a discharge valve 15, and the oil is transported into an oil tank 31. After the discharge valve 15 has been shut, an oil delivery valve lever 19 is operated to open an oil delivery valve 18, and oil that has passed through an oil filter 32 is returned to the oil vat 11 by driving an oil pump 33. However, because there is a limit to the filtering, oil that has exceeded a certain standard for the extent of oil degradation must be discarded. Naturally, after the oil has been discarded, new oil must be supplied.
Moreover, since oil is depleted because of absorption by the foods and evaporation through heating, it is necessary to periodically furnish oil to the oil vat 11, while the fryer 1 is in use.
Conventionally, the task of supplying oil involved putting the oil into a container, for example an industrial-size oil can, carrying the oil to the place where the fryer 1 was located, and then directly pouring the oil in the oil vat 11 from above. Also, the task of disposing of the oil involved attaching an oil discharge adapter (not shown in the drawings) to an oil discharge opening 14, so that the oil discharge adapter extended to the outside of the fryer 1, placing an empty can below the oil discharge adapter, discharging the oil, and then carrying away that can.
The oil supply task, however, required that the person performing that task to go through the trouble of carrying the oil to the fryer and then lifting the oil above the oil vat, thus making it a time-consuming task. Additionally, oil used for fryers is generally a solid oil at room temperature, for example shortening, thus making it necessary to first liquefy the oil before furnishing it into the empty oil vat. Thus, supplying oil that has been liquefied at a high temperature can be dangerous. Further, the task of discarding the oil is also a time consuming process as it requires man-power to carry the oil out of the fryer, and because the discarded oil is of a particularly elevated temperature, this work is dangerous as well. Moreover, when oil is added into the fryer while the fryer is in use, it is supplied into the fryer in a solid state without being liquefied, and there is the danger that high temperature oil in the oil vat would splash about and cause burns.
It is an object of the present invention to provide a fryer that solves the above problems, and in which the supply and discharge of oil is simple and safe.
To achieve the abovementioned object, a fryer in accordance with a first aspect of the present invention includes an oil vat for containing cooking oil; a heating means for heating the cooking oil in the oil vat; a filtering device for filtering the cooking oil in the oil vat when it is discharged into an oil tank; a return pipe serving as a duct for returning cooking oil in the filtering device to the oil vat; and an oil pump, disposed at an intermediate portion in the return pipe, for intaking cooking oil in the oil tank and pumping it to the oil vat, wherein, on the intake side of the oil pump, an oil supply pipe branches off from the return pipe, and an intake route switching means is provided for switching an intake route of the oil pump between the filtering device and the oil supply pipe.
A fryer in accordance with a second aspect of the present invention includes an oil vat for containing cooking oil; a heating means for heating the cooking oil in the oil vat; a filtering device for filtering the cooking oil in the oil vat when it is discharged into an oil tank; a return pipe serving as a duct for returning cooking oil in the filtering device to the oil vat; and an oil pump, disposed at an intermediate portion in the return pipe, for intaking cooking oil in the oil tank and pumping it to the oil vat, wherein, on the outflow side of the oil pump, an oil disposal pipe branches off from the return pipe, and an outflow route switching means is provided for switching the outflow route of the oil pump between the oil vat and the oil disposal pipe.
A fryer in accordance with a third aspect of the present invention includes an oil vat for containing cooking oil; a heating means for heating the cooking oil in the oil vat; a filtering device for filtering the cooking oil in the oil vat when it is discharged into an oil tank; a return pipe serving as a duct for returning cooking oil in the filtering device to the oil vat; and an oil pump, disposed at an intermediate portion in the return pipe, for intaking cooking oil in the oil tank and pumping it to the oil vat, wherein, on the intake side of the oil pump, an oil supply pipe branches off from the return pipe, and on the outflow side of the oil pump, an oil disposal pipe branches off from the return pipe; and wherein the fryer further comprises an intake route switching means for switching the intake route of the oil pump between the filtering device and the oil supply pipe, and an outflow route switching means for switching the outflow route of the oil pump between the oil vat and the oil disposal pipe.
In a fryer according to a first aspect of the present invention with the above configuration, the intake route switching means is used to switch the intake route of the oil pump provided for filtering oil from the oil tank to the oil supply pipes. By driving the oil pump, new oil for cooking is sucked in from the oil supply pipe and delivered to the oil vat by way of the return pipe, which is provided to serve as a filter return duct. Thus, using the filtration mechanism, new cooking oil can be supplied to the oil vat.
In a fryer according to a second aspect of the present invention, deteriorated cooking oil is discharged from the oil vat into the oil tank, the outflow route switching means is used to switch the outflow route of the oil pump, which is provided for oil filtration, from the oil vat to the oil disposal pipe. By driving the oil pump, deteriorated cooking oil is sucked in from the oil tank and discharged from the oil disposal pipe by way of the return pipe, which is provided to serve as a filter return duct. Thus, using the filtration mechanism, deteriorated cooking oil can be discharged from the oil vat.
In a fryer according to a third aspect of the present invention, oil can be supplied by a method similar to that of the fryer according to a first aspect of the present invention, and oil can be disposed of by a method similar to that of the fryer according to a second aspect of the present invention.